Complementary metal-oxide-semiconductor (CMOS) image sensor readout circuit designs have been developed in recent years. Most designs employ analog circuits, such as passive and active pixel sensors (APS). Subsequently, digital pixel image sensor designs were developed, which included approaches incorporating an oversampling sigma delta (ΣΔ) analog-to-digital converter at the pixel level and approaches that employ a Nyquist rate analog-to-digital converter at the pixel level. Digital pixel designs have several potential advantages over APS designs, including higher dynamic range and linearity, lower fixed pattern noise (FPN), and lower power consumption. The ΣΔ based image sensor designs have been demonstrated to have higher dynamic range than the APS and Nyquist rate digital image sensor designs.